Accuphase M-60 Love

[Phil M-W]

Phil that bridge rectifier is very similar to the one I used to fix one of of my 211 monoblocks a few months ago and documented on this forum.

Justin, I've only been on this forum 2 or 3 weeks and so far have only looked at 2 or 3 threads that caught my interest. If you are aware that they're available that's great.

I kinda feel your point that what's causing this issue is something that is failing when power is applied but looks fine when tested with power off.

Since everything seems to test OK when tested in isolation, it's what I'm leaning towards. It's what I would be looking at.

You might not know I replaced all the output transistors and used what seemed to be incredibly expensive thermal paste. I went for the best stuff I could find, though.

Ah, didn't know that, or it hadn't filtered through to my brain. What colour was the thermal paste? If it's grey or silver in colour, then it's likely to be silver loaded. It will be more expensive than the white aluminium oxide paste, simply because it has silver in it. It's generally more readily available because it's used by computer builders and there are a lot of them still about. It is preferred by them because it has better thermal conductivity, which if you're trying to prevent a CPU going into, in some cases a literal meltdown, it matters. The down side is, it's also electrically conductive (aluminium oxide is an insulator), which is why the instructions typically tell you not to apply too much, and if you do, to make sure you clean the excess off the board.
I don't know what you used, but it may be something to think about.
Phil